The following are the principal fractions obtained by the fractional distillation of crude oil.
1.Petroleum gas- These gases are liberated at the top of the cool at temperature below 40'C.They are mainly hydrocarbon consisting of one to four carbon atoms per molecule e.g methane,Ethan,propane,butane and ethene.They are used mainly as fuels for homes and industries and for the manufacture of products like hydrogen,carbon (IV) sulphide,tetrachloromethane and ethyne.
2.Petrole ethers- This mixture of very volatile liquids consists of hydrocarbon with five or seven carbon atoms per molecule.The petroleum ether or light petroleum distils over between 2'C to 60'C while the light naphta distills over between 60'C to 100'C.Both the product are used as organic solvents.
3.Petrol: Petrol is a mixture of hydrocarbon considering of four to twelve carbon atoms per molecule.It is a volatile liquid which distills over in temperature range of 40'C to 200'C.Petrol is used as a fuel for Aeroplan and motor-vehicles.It is also a good solvent for paint and grease.
4.Kerosene: Kerosene contains hydrocarbons with twelve to eighteen carbon atoms per molecule.It distills over in the temperature range of 200'C to 250'C.It is a fairly volatile liquid and is used as a fuel for lighting and heating and for driving tractors and some modern jet engine.
5.Gas oil and diesel oil: These are mixture of hydrocarbon with twelve to twenty-five carbon atoms per molecule.They distills over in the temperature range of 250'C to 350'C.They are used mainly as fuels for heating and diesel engine and as a raw material for cracking process.
6.Lubricating oil: These are heavy oils.They consist of hydrocarbon with more than twenty carbon atoms per molecule, which distills over in the temperature ran